abstract   background: the x-ray machines used for radiodiagnosis should meet certain quality assurance (qa) programmes . these are necessary to have good quality radiographs at reasonably low exposure to patients.   materials and methods: dose reduction methods in abdomen x-ray examination were carried out in 10 hospitals in tehran. this paper presents the work, which was implemented on 200 pa...

THE movement for health care quality improvement has many of the features of a religion. There are gurus — leaders whose ability to communicate their ideas and beliefs gives them a great deal of power and influence. There are adherents or followers who adopt those ideas and beliefs wholeheartedly and find great strength and comfort in the community of fellow believers. There are belief systems ...

In this paper we study the optimal file-sharing mechanism in a peer-to-peer network with a mechanism design perspective. This mechanism improves upon existing incentive schemes. In particular, we show that peer-approved scheme is never optimal and service-quality scheme is optimal only under certain circumstances. Moreover, we find that the optimal mechanism can be implemented by a mixture of p...

results before the intervention, there were no significant differences between mothers in two groups (p > 0.05). after 8 weeks follow up, a significant improvement appeared in mothers’ sleep quality in the intervention group. aromatherapy increased sleep quality mean score (±sd) from 8.2911 (± 2.1192) to 6.7975 (± 2.3663) (p < 0.05), but in the control group sleep quality mean score (±sd) chang...

This paper extends an imperfect production inventory model to machine breakdown at a random time and rework of defective items. Any manufacturing system wants to produce perfect quality items. But in long run production process, there may arise different types of difficulties like labor problem, rawmaterial problems, operator problems, etc., due to that the machinery systems shift from in-contr...

PURPOSE The degree of lung inflation seen on a chest radiograph is dependent on the point during the patient's respiratory cycle at which the radiographer exposes the image receptor. Exposing the image receptor at the exact peak of inflation can be difficult because of the limited time available in which to capture the inspiratory pause. An incentive spirometer can indicate the moment of peak i...